1. Field of the Invention
The present invention relates to a superconducting coil and a superconducting rotating machine, especially the superconducting coil to be used for a stator coil of the superconducting rotating machine and the superconducting rotating machine utilizing the stator.
2. Description of Related Art
The superconducting rotating machine utilizing the superconducting coil of a superconducting material has been known as enabling a rotating machine that is smaller and lighter.
JP2005-176578A discloses a superconducting motor (superconducting rotating machine) with a stator coil of a superconducting coil on a stator. The superconducting coil (stator coil) disclosed in JP2005-176578A consists of a tape of a superconducting material that is coiled in a race-track shape with linear portions and curved portions. In each turn of this superconducting coil, the linear portion of the tape is on the same plane as the curved portion of the tape.
JPH08-236341A discloses a saddle shape superconducting member which has a linear portion of a stator coil is not disposed on the same plane as a curved portion of the stator coil, which is intended to have the linear portion of the stator coil come close to a rotor and not to have the curved portion of the stator abut on stator. JP2009-049040A discloses a coil frame on which a tape of a superconducting material is coiled.
Looking to any of JP2005-176578A, JPH08-236341A and JP2009-0490040A, a shape of a stator tooth, on which a shaped coil is attached, is restricted because there is no way to change a coil shape after the coil is shaped. For example, if the shape of a stator tooth is homogeneous in the radius direction of the super conducting rotating machine like the superconducting motor (superconducting rotating machine) shown in FIG. 2 of JP2005-176578, any of the superconducting coils disclosed in JP2005-176578A, JPH08-236341A and JP2009-049040A can be attached onto the stator tooth without deforming the shape of the superconducting coil.
However if the width of a stator tooth varies in the radius direction of the superconducting rotating machine, it may be difficult to attach any of the superconducting coils disclosed in JP2005-176578A, JPH08-236341A and JP2009-0490040A onto the stator tooth. For instance, if the width of a portion of a stator tooth becomes larger as the portion is farther apart from the center of a rotation axis of a rotor in the radius direction of the superconducting rotating machine, the superconducting coil has to be attached onto the stator tooth while enlarging the coil width and it is difficult to attach any of the superconducting coils disclosed in JP2005-176578A, JPH08-236341A and JP2009-0490040A onto the stator tooth because the shape of any of these superconducting coils can not be changed.